Combination switch and rheostat



P 1935. N. c. SCHELLENGER 2,014,637

COMBINATION SWITCH AND RHEOSTAT Filed Nov. 27, 1931 MWWM Patented Septf 17, 1935 UNITED STATES PATENT (OFFICE COMBINATION SWITCH AND RHEOSTAT Newton 0. Schellenger, Emmi-t; Ind., assignmto Chicago Telephone Supply Company, Elkhart, Ind., a corporation of Indiana 6 Claims.

My invention relates to a combination switch and rheostat.

It is common practice in modern radio sets and the like to provide a single knob which is turned first to operate a switching device by which the set is connected to a source of power, and subsequently turned to adjust the volume of sound produced by the radio set. In devices of this kind the operating member moved by the control knob to actuate the switch mechanism is adapted to engage the switch mechanism only when the volume control knob is in or near its off position, and to be disengaged from the switch mechanism as soon as that mechanism has been operated. The movable member of the volume control mechanism is thus reduced to the minimum necessary for the controlof the volume of the radio set, to permit accurate adjustment of that movable member throughoutthe working range of the volume control. b

In the prior art devices of which I am aware considerable dilhculty has been experienced in maintaining a proper alignment between the switch mechanism and the movable member of the volume control unit. Any misalignment of these two mechanisms makes it diflicult if not impossible to bring the operating means carried by the movable member of the volume control into operative relation with the switch mechanism. In certain instances such misalignment may also make it difficult to disengage the oper- I ating member carried by the volume control element from the switch mechanism when that switch mechanism has been moved to its operative or closed position; I My invention provides as its principal object a new andimproved combined volume control unit and switch mechanism in which an accurate alignment of the parts is assured, a device which is of rugged simple design that can be fabricated at a low cost without sacrificing quality.

In the preferred embodiment of my invention the volume control unit is housed in a cup-like shell in which a shaft is concentrically journaled. The contacting member of the volume control unit and the operating member of the switch I element are mounted upon this shaft. The volume control shell is closed by a cover plate upon which a suitable switching mechanism is securely mounted. The cover is definitely located with respect to the shell by suitable means on the shell accurately registered with it and positively, engaged by a cooperating means carried by the cover. Since the switching mechanism is securely attached to the cover member, it is defitaken along the line nitely located with respect thereto, and by dc!!- nitely locating the cover with respect to the shell of the volume control unit the operating member carried by the shaft of that unit can be properly registered with the operating element of the switching device. Since the operating member is properly aligned with respect to" the switching mechanism, it can be easily moved into and out of engagement therewith, and the faults encountered in prior art devices of which I am aware are thereby eliminated. j

My invention will be best understood by reference to the accompanyingdrawing in which a preferred embodiment of it is shown by way 0! example and in which: 15 Figure lis a perspective view of a completely assembled unit;

Figure 2 is an elevational view of the completely assembled unit, partly in section, and showing the operating means engaged with the switch 20 mechanism;

Figure 3 is a plan view of the inside face of the cover showing the switch mechanism mounted thereon;

Figure 4 is a fragmentary cross sectional view 5 similar to Figure 4 and showing the cover'looked g in place; r v :30 Figure 6 is a fragmentary cross sectional-view" 6-6 of Figured looking in the direction of the arrows;

Figure '7 is a fragmentary cross sectiol ne tail of a modified form of my invention; Figure 8 is a fragmentary plan view showing? the mode of engaging and disengaging thefop crating means from the switch mechanism.

Referring now to the drawing in more detail,

the device of my invention consists of a rheostat 40 a switch mechanism 3 mounted upon the cover. For convenience the rheostat I is herein termed a volume control, although obviously the-cover 2 and switch 3 may be mounted upon any rheostat or similar device. 45 The rheostat unit comprises a plate ti having a cylindrical flange 5 disposed at its outer periphery. A shaft 6 is journaled in a suitable bushing located concentrically of the plate Q, this bushing i being threaded for the reception of a nut 50 8 by which the unit is mounted upon a suitable supporting member 9. r

The members 4 and 5 may be I, a cover 2'and integral parts i of a metallic cup-like shell or integral parts of I material such as a phenol condensation produc Located within the shell is a resistance element l spaced from the walls of the shell by spacing members II and I2, and retained in the shell in any preferred manner such as by the rivet l3 which also serves as a support for one of the terminal elements l4 of the device.

Located ,upon the end of the shaft 5 and butted against the end of the bushing 1 is a contact arm l5 carrying a contactor l6 which is pressed against the resistance element l0 by a compression spring H. The details of the construction of the contact arm l5 and the contacting elements l6 and H are not of the essence of the present invention, the structure shown being taken from my copending application Serial No. 518,281, filed February 25, 1931 and shown by way of example only.

A plurality of outwardly projecting bosses 20 having straight parallel sides 2| are located in the free edge of the cylindrical wall 5 of the shell. In Figures 4, 5and 6 I have shown these bosses formed in a metallic shell member 5 by forcing a portion 20 of the peripheral edge of that shell outwardly of the main body portion. In Figure. 7 I have shown the boss 20' as a projection formed integrally with the wall member 5' of a molded shell member. In either case, the bosses 20 are provided with parallel straight side faces 2| and 22 as shown in Figure 6.

The cover member indicated generally at 2 preferably comprises a metallic disc 23 having a cylindrical flange 24 located at its outer periphery. The inside diameter of the flange 24 is accurately maintained to the outside diameter;

of the cylindrical portion 5 of the shell I so that the cover will snugly fit upon the shell.

Locatedupon the plate 23 of the cover 21s a switch element 3 comprising a molded switch shelf 25 in which are located the switching devices indicated generallyat 25 in Figure 3. The.

particular type of switching element used in combination with the rheostat is not of the essence of my present invention. Any preferred type of switch mechanism may be used for this purpose within the teachings of the invention. The switch element 3, shown by way of example, is the switch shown and more fully described in my copending application, Serial No. 602,006, filed March 30, 1932, to which application reference is here made for the details of construction of the switch.

The housing 25 of the switching device 3 contains a plurality of locating bosses 33. Slots 34 are provided in the plate 23 of the cover 2. In the assembly of the unit these bosses 33 are registered with the slots 34 an the switch is locate definitely with respect to e plate 23.

The flange 24 of, the cover contains a plurality of parallel sided slots 26 corresponding in number to the number of projections 20 upon the shell flange 5. These slots 26 are made by cutting the edge of the flange 24 and forcing the metal of the cut portion outward to form tongues 21. The width of the slots 26 corresponds accurately with the length of the bosses 20, that is, the distance between parallel faces 2| and 22.

The operation of forming the tongues 21 out of the surface of the flange 24 forms shoulders 28 inside of the tongues and at the bottom of the grooves 26. The operation of forming the bosses 20 forms flat ends 29 which are somewhat wider than the thickness of the wall 5. The flat ends 29 of the bosses are abutted against the shoulders ends of the bosses 20 on theshell member I are 5 likewise formed equidistant from and parallel to the plate portion 4 of that shell. "As a result when these two shoulders are abutted together the cover is definitely located on the shell with its v plate or disc portion 23 parallel to and at a fixed distance from the disc portion 4 of the shell.

Since the width of the grooves 26 in the cover member 2 is such that the'walls thereof accurately engage the parallel ends 2| and 22 of the bosses 20, the cover is also definitely positioned upon the shell, that is, the cover is located and fixed against rotation about the axis of the shell. As will be seen in Figures 4, 5 and 7 the bosses project outwardly from the flange portion 5 of the shell a distance equal to the thickness of 20 I the flange portion 24 of the cover member. The

tongues 21 are displaced out of the flange portion 24 a distance slightly greater than the thickness of the tongues so that when the cover is placed upon the shell the tongues will pass v freely past the outer surfaces of the bosses 20. After the cover has been properly located upon the shell, the free ends of the tongues 21 are bent over against the lower and outer surfaces 30 of the bosses 20 in the manner shown at 3| 30 in Figure 5. This forming of the tongues is a crimping action which draws the shoulders 28 of the cover tightly down upon the shoulders 29 of the shell bosses 20 and insures proper alignment of the cover in all directions .with respect to the shell. N

As shown, there are four bosses 20 upon the shell and four ears 21 upon the cover. This particular arrangement may be varied within the teachings of my invention. 1 have found that with an arrangement of this kind the cover is very securely attached to the shell and capable of withstanding a tension of approximately sixty pounds tending to. pull the two apart. This strength is greatly in excess of any stresses that are liable to be put upon the cover'to separate it from the rheostat shell.

Located on the pivot 40 of the switch mechanism 25' is an operating member 4| containing ears 42 which project outwardly from the switch. -These ears 42 project through a perforation 44 mechanism carries an operatingpin which is securely seated in a boss IS in that arm. This pin 43 engages with and fits between the two projecting arms 42 of the switch element when the contacting arm I5 is positioned at or near the off position of the rheostat. A' movement of the e0 contacting arm towards one of its limiting or and positions will engage the pin 43 with one of the ears 42 and rotate the member about its pivot 40 to thereby operate the switch mech-. anism and move the contacting members thereof together to close a circu t through the switch. After the switch has been thus operated the operating pin 43 is moved out of engagement with the ears 42. A movement of the contacting arm I5 in a reverse direction will re-engage the pin 43 with the ear 42 and operate the member 4| in a reverse direction'toopen the circuit closed through the switch, that circuit being opened simultaneously with the arrival of the contactage and disengage them.

40 is fixed upon the switch shell 25 and since that shell is fixed upon the cover member 23, the accurate positioning of the cover on the rheostat shell definitely fixes the pivot 40 with respect to the contacting arm l5 and pin 43 carried thereby. The cars 42 are thus-located with respect to the pin 43 so that that pin may easily en- In Figure 8, I have illustrated the manner in which the pin 43 is engaged with and disengaged from the lever M. In this figure lever 4| is shown in solid lines in the position it assumes when the switch mechanism is closed. The path in whichthe operating pin 43 travels is designated by the dot dash line 45. It will be noted that as the pin is moved counterclockwise along this path, as in the case of returning the contactor arm IE to its normal or off position, the pin passes into the open end of the lever 4|, that is, between the ears 42. The left hand ear 42 is completely out of the path of the pin. The

.right hand ear 42 lies in this path and is engaged by the pin. The lever is rotated about its pivot to the position shown in dotted lines at the right hand side of the figure, and the switch contacts are opened by this movement. The pin 43 comes to rest in the position shown in dotted lines at the right hand side of Figure 8.

This movement of the lever 4| about its pivot swngs the right hand ear 42 out of the path of the pin 43 and swings the left-hand ear 42 into that path. A movement of the pin .43 in a reverse direction, that is, clockwise in its path, will instances space in a radio set or other similar device is at a premium and it is advantageous to have the space occupied by a sub-assembly of that device efllciently used.

The employment of .projecting bosses on the shell member for cooperating with an element on the cover to locate the cover on the shell lends itself well to use on rheostat shells made of formed metal and also on shells made of molded insulation. The cost of fabrication is low in either case. The square accurately located ends 29 of the bosses cooperating with shoulders upon the cover definitely locate that cover on the shell and space it sufllciently far away from the ends of the rheostat that there is no danger of flashover due to potential differences between the l. The combination of a cup-like shell for a rheostat, substantially parallel sided bosses projecting radially outwardly from the free edge of said shell, a cover comprising a plate and a cylindrical flange extending from the free edge thereof, said flange having slots in its free edge, and tongues extending outwardly from the bot-- 5 toms of said slots, said flange registering with said shell and said bosses with the sides and bottoms of said slots to locate the'cover on the shell, and said tongues being bent inwardly over I said bosses to hold the cover in place on the 10 shell.

2. The combination of a shell comprising a disc and a flange upstanding from the edge thereof, bosses thrown outwardly. from the free edge of said flange, said bosses containing fiat end sur- 15 faces disposed parallel to and equidistant from said disc, a cover for said shell comprising also a disc and a flange upstanding from the edge thereof, the inside diameter of said cover flange being sufiicient to permit the cover flange to snugly 20 fit over the shell flange, walls defining slots in said cover flange into which said .bosses snugly each side wall, the projections of cooperating 'side 35' walls positioned in telescopic relationship and bent into engagement with each other to fasten said side walls to each other in non-rotatable and non-translatory position.

4. Ina receptacle, in combination, telescopi- 40 cally cooperating side walls, projecting members struck from the surface of each side wall, the projecting members of one side wall positioned in over-lapping relationship tothe projecting members of the other side wall and bent around 45 said last named projecting members, whereby the said side walls are held in fixed relationship to each other and are locked in non-rotatable and non-translatory engagement.

s 5. In a receptacle, in combination, a shell and 50 a cover having telescoping side walls, a plurality of bosses extending outwardly from the inner member,-a plurality of registering tongues struck out from the cover, the bases of the cover tongues engaging the bosses to limit inward movement 55 of the shell and cover, and the cover tongues being bent around the bosses to prevent separation of the shell and cover.

6. In a receptacle, in combination, a shell and a cover having telescoping side walls, a plurality 60 of bosses extending outwardly from the inner member, a plurality of registering tongues struck out from 'the cover, the tongues being of substantially equal width with the bosses, the bases of the cover tongues engaging the bosses to limit inward movement of the shell and cover, the cover wall adjacent the base of the cover tongues engaging the sides of the bosses to prevent rela-' tive lateral movement of the shell and cover, and the cover tongues being bent around the bosses 70 to prevent separation of the shell and cover.

NEWTON C. SCHELLENGER.

' Patent No. 2 014, 637.

cm mchmoreeRREcTIeN.

Niiwmy c. iSCfiELLENGER. i

It is'hereby certified that errer appears 'in'the printed specification of 'the above numbered patent requiring correetion'as' follows: Psgei3T second column, line 26, 'claim 2, before 1"end" insert the word flat; andthat the said Letters Patent should be read with this'correction therein that the same may conform to the record of the ease in the Patent Office.

'- Signed and sealed this 5th at; of N0 vember, A.12,1931

' Leslie Frazer (Sea'l) f ActihzCoinm i ssioner of Pate ts..

I September l7.i985Q Q 

